Support device for a snowplough blade

ABSTRACT

The support device for a snowplough blade comprises a body produced in one piece and defining: a reservoir, pumping means and support means for the blade, the pumping means being fed by the reservoir and operating the support means for the blade.

FIELD OF THE INVENTION

The present invention relates to a support device for a snowploughblade.

BACKGROUND OF THE INVENTION

Snowplough blades are currently mounted on and manipulated by suitablevehicles provided with support devices which are very heavy and bulky.

DISCUSSION OF THE RELATED ART

For example, a blade support system typically presents a plurality ofhydraulic cylinders for supporting and swivelling the blade and aplurality of valves and control and safety systems connected together,which make the device extremely heavy and bulky.

Because of the considerable weight and large dimensions of traditionaldevices a snowplough blade cannot be mounted on “generic” vehicles evenif these are of very large dimensions and engine power, such as SUVs.

SUMMARY OF THE INVENTION

The technical aim of the present invention is therefore to provide asupport device for a snowplough blade which enables the stated technicaldrawbacks of the known art to be eliminated.

Within the scope of this technical aim an object of the invention is toprovide a device of small dimensions and weight such that it can also bemounted on a vehicle of generic type (i.e. not specifically designedtherefore) without the risk of this overturning because of the weight.

Another object of the invention is to provide an economical device.

The technical aim together with these and further objects are attainedaccording to the present invention by a support device for a snowploughblade in accordance with claim 1.

Other characteristics of the present invention are defined in thesubsequent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Further characteristics and advantages of the invention will be moreapparent from the description of a preferred but non-exclusiveembodiment of the device of the invention, illustrated by way ofnon-limiting example in the accompanying drawings, in which:

FIG. 1 is a perspective view of a device of the invention;

FIG. 2 is a circuit diagram of the device of the invention (including asecond swivel cylinder for the snowplough blade);

FIG. 3 is a schematic perspective view of a snowplough blade mounted ona vehicle; and

FIG. 4 is a schematic side elevation (partly sectioned) of a vehiclecarrying a snowplough blade.

DETAILED DESCRIPTION OF THE INVENTION

With reference to said figures, these show a snowplough blade supportdevice indicated overall by the reference numeral 1.

FIG. 3 shows a “generic” motor vehicle (such as a SUV) on which a deviceof the invention is mounted to support a snowplough blade 3.

The blade 3 is used to shift snow while the vehicle 2 is travelling; itsposition can be adjusted vertically (as indicated by the arrow F1) orhorizontally (as indicated by the arrow F2).

Specifically, the device 1 comprises a body 5 produced in one piece bycasting; the body 5 defines a reservoir 6, pumping means 7 (consistingof a gear pump connected to a preferably electric motor powered by thevehicle battery) and support means 8 for the blade 3; the pumping means7 are fed by the reservoir 6 and operate the blade support means 8.

The support means 8 comprise a first hydraulic cylinder for raising theblade; as shown in FIG. 1 this first cylinder 8 is defined by the body 5and within it there moves a piston rod 9 the end of which carries athrough holed seat 10 for connection to the blade 3.

The first hydraulic cylinder 8 is single acting (only one of itschambers is fed by the fluid from the pump 7) and operates against theaction of a spring, consisting of an air spring formed in the firsthydraulic cylinder 8 at the opposite end to that comprising the inletand outlet for the operating fluid originating from the pump 7.

The first cylinder 8 is also connected to a unidirectional valve 13enabling air to enter its interior at that chamber 12 of the firstcylinder 8 which defines the spring, only when the cylinder piston rodre-enters the cylinder.

Alternatively the chamber 12 can be pressurized and can containpressurized fluid (gas) to increase the elastic thrust.

For regulating the (maximum) pressure of the first cylinder 8, thedevice 1 comprises a regulating valve 14 connected in parallel with thevalve 13.

The device also comprises a second hydraulic cylinder 17 for definingthe lateral orientation (or swivelling) of the blade 3.

Preferably the second cylinder 17 is external to the body 5, which (body5) presents two connectors 18, 19 for connection to the second cylinder17.

The second cylinder 17 is a double acting cylinder (for this reason twofeed/discharge connectors are required), consequently the body 5presents two connectors 18, 19 for feeding the second cylinder 17.

As shown in FIG. 2, the device comprises only one second cylinder 17connected to one side of the blade 3; the blade 3 also presents a hinge20 (for example of ball type to enable it to be vertically adjusted andswivelled) for its hinging to a frame of the vehicle 2 on its transverseaxis of symmetry.

The body defines a plurality of conduits defining the feed circuit ofthe first and second cylinder.

The body 5 also presents, for feeding the connectors 18, 19, a feedcircuit comprising at least one control valve 22, a bypass valve 23 anda non-return valve 24.

The feed circuit for the connectors 18, 19 comprises a recirculationvalve 25 for the operating liquid leaving one of the chambers of thesecond cylinder 17, to feed it into the other chamber of the secondcylinder 17.

The device also comprises a control valve 26 for deviating the flow ofoperating liquid delivered by the pump 7 from the first cylinder 8 tothe second cylinder 17 and vice versa, to enable both the first cylinder8 and the second cylinder 17 to be operated by a single pump 7.

A further unidirectional valve 27 is positioned in the line between thereservoir 6 and the first cylinder 8, to enable or prevent fluid passagethrough said line, and hence connect or not connect the reservoir to thefirst cylinder 8.

The operation of the device according to the invention is apparent fromthat described and illustrated, and is substantially the following.

The first cylinder 8 is operated by connecting it to the pump 7 via thevalve 26; the pump 7 feeds liquid which enters the cylinder 8 bycompressing the air contained in the chamber 12 (which is unable toleave via the unidirectional valve 13); if a safety pressure is exceededthe valve 14 would automatically open to discharge air to the outside.

When the blade 3 has been brought into the required (vertical) position(adjustment in the direction of the arrow F1), the cylinder 8 isisolated by setting the valve 26 and valve 27 in the configuration shownin FIG. 2; in this manner the piston rod of the cylinder 8 is unable tore-enter the cylinder because the liquid (incompressible oil) is unableto leave the isolated cylinder 8, and at the same time a force existswhich urges the piston rod towards the interior of the cylinder 8 (asindicated by the arrow F), which ensures that the position of the pistonrod and hence of the blade 3 is maintained.

The blade is raised by operating the valve 27 so that it closes thecircuit into which it is connected, in order to enable the liquidcontained in the cylinder 8 to discharge into the reservoir 6.

The cylinder 17 is operated by suitably controlling the valves 22, 25.

Specifically, to cause the piston rod of the cylinder 17 to emerge fromthe cylinder (as indicated by the arrow F4) the valve 22 is kept open(as shown in FIG. 2) while the valve 25 is closed (enabling liquid topass through it); in this manner the liquid pumped by the pump 7 passesthrough the valve 24 and the valve 25, passes through the connector 18and enters the chamber 17 a of the cylinder 17; at the same time thefluid leaving the chamber 17 b passes through the connector 19 andthrough the valve 25 to also enter the chamber 17 a.

The cylinder is operated in the direction of the arrow F5 by leaving thevalve 25 open and closing the valve 22 (so that this can be traversed bythe fluid); in this case the fluid pumped by the pump 7 passes throughlo the valve 24 and the connector 19 to penetrate into the chamber 17 bof the cylinder 17.

The fluid leaving the chamber 17 a of the cylinder 17 passes through thevalve 22 to reach the intake side of the pump 7.

The bypass valve 23 enables the blade 3 to swing if it is strucklaterally.

It has been found in practice that the device of the invention isparticularly advantageous as it is very economical and light in weight,and can be easily mounted on generic vehicles.

The device conceived in this manner is susceptible to numerousmodifications and variants, all falling within the scope of theinventive concept; moreover all details can be replaced by technicallyequivalent elements.

In practice the materials used and the dimensions can be chosen at willaccording to requirements and to the state of the art.

1. A support device for a snowplough blade comprising a body produced inone piece and defining: a reservoir, pumping means and support means forthe blade, wherein the pumping means are fed by the reservoir andoperate the support means for the blade.
 2. A device as claimed in claim1, wherein the support means comprise a first hydraulic cylinder forraising the blade, said first cylinder being defined by said body.
 3. Adevice as claimed in claim 2, wherein said first hydraulic cylinder issingle acting and operates against the action of a spring.
 4. A deviceas claimed in claim 3, wherein said spring is an air spring formed insaid first hydraulic cylinder at the opposite end to that comprising theinlet and outlet for the operating fluid.
 5. A device as claimed inclaim 4, wherein said first hydraulic cylinder is connected to aunidirectional valve enabling air to enter its interior at that end ofthe first cylinder which defines the spring, only when the cylinderpiston rod re-enters said cylinder.
 6. A device as claimed in claim 2,further comprising a regulating valve for regulating the pressure ofsaid first cylinder.
 7. A device as claimed in claim 1, wherein saidsupport means comprise a second hydraulic cylinder for defining thelateral orientation of said blade.
 8. A device as claimed in claim 7,wherein said second cylinder is external to said body, said bodypresenting at least one connector for connection to said secondcylinder.
 9. A device as claimed in claim 7, wherein said secondcylinder is a double acting cylinder, said body presenting twoconnectors for feeding the second cylinder.
 10. A device as claimed inclaim 7, further comprising only one second cylinder connectable to oneside of said blade, said blade presenting a hinge for its hinging to aframe on its transverse axis of symmetry.
 11. A device as claimed inclaim 8, wherein said body presents, for feeding said connectors, acircuit comprising at least one control valve, a bypass valve and anon-return valve.
 12. A device as claimed in claim 11, wherein saidcircuit feeding said connectors comprises at least one valve forrecirculating the operating liquid leaving a chamber of the secondcylinder, to feed it into the other chamber of said second cylinder. 13.A device as claimed in claim 2, further comprising a control valve fordeviating the flow of operating liquid delivered by the pumping meansfrom the first cylinder to the second cylinder or vice versa, to enablesaid first cylinder and said second cylinder to be operated by a singlepumping means.
 14. A device as claimed in claim 2, wherein aunidirectional valve is positioned in the line between the reservoir andthe first cylinder.